package cn.hdufocus.focus_helper.shiro;

import cn.hdufocus.focus_helper.entity.User;
import cn.hdufocus.focus_helper.service.IUserService;
import cn.hdufocus.focus_helper.util.JWTUtil;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.apache.shiro.authc.AuthenticationException;
import org.apache.shiro.authc.AuthenticationInfo;
import org.apache.shiro.authc.AuthenticationToken;
import org.apache.shiro.authc.SimpleAuthenticationInfo;
import org.apache.shiro.authz.AuthorizationInfo;
import org.apache.shiro.authz.SimpleAuthorizationInfo;
import org.apache.shiro.realm.AuthorizingRealm;
import org.apache.shiro.subject.PrincipalCollection;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.Arrays;
import java.util.HashSet;
import java.util.Set;

    @Service
    public class MyRealm extends AuthorizingRealm {

        private static final Logger LOGGER = LogManager.getLogger(MyRealm.class);
        @Autowired
        private IUserService userService;


        /**
         * 大坑！，必须重写此方法，不然Shiro会报错
         */
        @Override
        public boolean supports(AuthenticationToken token) {
            return token instanceof JWTToken;
        }

        /**
         * 只有当需要检测用户权限的时候才会调用此方法，例如checkRole,checkPermission之类的
         */
        @Override
        protected AuthorizationInfo doGetAuthorizationInfo(PrincipalCollection principals) {
            String username = JWTUtil.getUsername(principals.toString());
            User user = userService.getUser(username);
            SimpleAuthorizationInfo simpleAuthorizationInfo = new SimpleAuthorizationInfo();
            simpleAuthorizationInfo.addRole(user.getRole());
            Set<String> permission = new HashSet<>(Arrays.asList(user.getPermission().split(",")));
            simpleAuthorizationInfo.addStringPermissions(permission);
            return simpleAuthorizationInfo;
        }

        /**
         * 默认使用此方法进行用户名正确与否验证，错误抛出异常即可。
         */
        @Override
        protected AuthenticationInfo doGetAuthenticationInfo(AuthenticationToken auth) throws AuthenticationException {
            String token = (String) auth.getCredentials();
            // 解密获得username，用于和数据库进行对比
            String username = JWTUtil.getUsername(token);
            if (username == null) {
                throw new AuthenticationException("token invalid");
            }

            User user = userService.getUser(username);
            if (user == null) {
                throw new AuthenticationException("User didn't existed!");
            }

            if (! JWTUtil.verify(token, username, user.getPassword())) {
                throw new AuthenticationException("Username or password error");
            }
            return new SimpleAuthenticationInfo(token, token, "my_realm");
        }
    }
